// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_OBJECTS_FREE_SPACE_INL_H_
#define V8_OBJECTS_FREE_SPACE_INL_H_

#include "src/objects/free-space.h"

#include "src/heap/heap-write-barrier-inl.h"
#include "src/heap/heap.h"
#include "src/isolate.h"
#include "src/objects-inl.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

    OBJECT_CONSTRUCTORS_IMPL(FreeSpace, HeapObject)

    SMI_ACCESSORS(FreeSpace, size, kSizeOffset)
    RELAXED_SMI_ACCESSORS(FreeSpace, size, kSizeOffset)

    int FreeSpace::Size() { return size(); }

    FreeSpace FreeSpace::next()
    {
#ifdef DEBUG
        Heap* heap = GetHeapFromWritableObject(*this);
        Object free_space_map = Isolate::FromHeap(heap)->root(RootIndex::kFreeSpaceMap);
        DCHECK_IMPLIES(!map_slot().contains_value(free_space_map->ptr()),
            !heap->deserialization_complete() && map_slot().contains_value(kNullAddress));
#endif
        DCHECK_LE(kNextOffset + kTaggedSize, relaxed_read_size());
        return FreeSpace::unchecked_cast(*ObjectSlot(address() + kNextOffset));
    }

    void FreeSpace::set_next(FreeSpace next)
    {
#ifdef DEBUG
        Heap* heap = GetHeapFromWritableObject(*this);
        Object free_space_map = Isolate::FromHeap(heap)->root(RootIndex::kFreeSpaceMap);
        DCHECK_IMPLIES(!map_slot().contains_value(free_space_map->ptr()),
            !heap->deserialization_complete() && map_slot().contains_value(kNullAddress));
#endif
        DCHECK_LE(kNextOffset + kTaggedSize, relaxed_read_size());
        ObjectSlot(address() + kNextOffset).Relaxed_Store(next);
    }

    FreeSpace FreeSpace::cast(HeapObject o)
    {
        SLOW_DCHECK(!GetHeapFromWritableObject(o)->deserialization_complete() || o->IsFreeSpace());
        return bit_cast<FreeSpace>(o);
    }

    FreeSpace FreeSpace::unchecked_cast(const Object o)
    {
        return bit_cast<FreeSpace>(o);
    }

} // namespace internal
} // namespace v8

#include "src/objects/object-macros-undef.h"

#endif // V8_OBJECTS_FREE_SPACE_INL_H_
